<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--浏览器中居然还真跑起来了-->
<script src="https://unpkg.com/vue/dist/vue.js"></script>
<div id="app">
    <p>{{count}}
        <button @click="inc">+</button>
        <button @click="dec">-</button>
    </p>
</div>
<script>
    new Vue({
        el:'#app',
        data () {
            return {
                count: 0
            }
        },
        methods: {
            inc () {
                this.count++
            },
            dec () {
                this.count--
            }
        }
    })
</script>

</body>
</html>